(Intro)

Michael Aranda: Ladies and gentleman, welcome to SciShow Quiz Show! The show where we do the research, and it's probably all true!

Today we have the ultimate SciShow showdown, between SciShow host: Hank Green, and SciShow writer: Dave Loos.

Hank Green: Hi, Dave.

Dave Loos: Hi, Hank.

HG: How's it going?

MA: (Giggles)

(Explosion)

MA: Hank! 

HG: YES!

MA: You are competing on behalf of Paul Andrews.

HG: Hi, Paul!

MA: Dave, you are competing on behalf of Daven Hiskey.

DL: Alright, Daven.

MA: Stefan, tell the viewers at home what Paul and Daven could win!

Stefan: Well Michael, both Paul and Daven will be taking home autographed cards from Hank and Dave; with their final guesses and wagers on them.

As well as either the "I Won SciShow Quiz Show" pin, or the highly sought after "I Lost SciShow Quiz Show" pin.

And the winner will also take home a copy of the script from this episode.

Thank you for playing our game, Paul and Daven! Back to you, Michael!

(Explosion)

MA: Both of you guys start off with 1000 SciShow points. Each time you answer a question correctly you get 100 points. If you answer a question incorrectly, or don't answer, you will lose 100 points.

HG: So if I go first, and I get it right, I get 100 points, and Dave loses 100 points?

MA: Correct.

DL: (Noise of disdain) That's a new button since last time.

MA: False.

HG: Nooo! Same button.

MA: That's minus 100 points!

DL: Oh. really?

HG: 'Cause it's same button!

DL: Really?

MA: Okay! (Clears throat)

HG: We have not gotten a new button.

As you can tell by the fact that it does not work.

MA: You guys ready?

HG: Yes!

MA: Okay, round 1 is about diamonds! 

They're shiny, and usually pretty expensive, but diamonds also happen to have some of the most useful properties you'll find in a material. They're so hard that rough diamonds are used in industry from to everything cutting to polishing.

But people also like to use them for jewelry. One of the characteristics used to distinguish a diamond is color. Diamond crystals are made of very rigid, 3-D arrangements of carbon atoms into a structure called a lattice. Certain impurities -or shifts in that lattice structure- can change the way crystal absorbs light; affecting its color, which is why diamonds can be pink, or yellow, or green, or brown or even black.

In the case of a brown diamond, for example, the color comes from the way the lattice is distorted by heat and pressure in the ground as it forms.

Now, blue diamonds: what makes a blue diamond blue?

Is it: there's extra nitrogen in the rock around the diamond when it formed?

Some of its carbon atoms were replaced by boron atoms?

It absorbed radiation from the ground?

Or brief colder periods during its formation changed its structure?

(Buzzer)

HG: Ima say: that thing about boron.

MA: You are correct!

HG: Yeah! That sounds cool!

MA: Yeah!

DL: That was the longest question.

HA: (Laughs)

Sciencey MA: Diamonds turn blue when they incorporate boron into their crystals; where normally there'd be carbon.

Boron and carbon are similar sizes, but there's a big difference between them -besides the fact that they're totally different elements. Carbon has 4 electrons available for bonding; while boron only has 3.

That gives the crystal some weird properties: like absorbing red light and reflecting the bluer end of the spectrum.

And the boron impurities actually make the blue diamonds work like semiconductors; as opposed to other diamonds, which are good electrical insulators.

So if you ever get your hands on the Hope Diamond, you could use it to complete a circuit.

MA: Round 2 is three questions about how humans are weird.

HG: Agreed.

MA: The things that you eat can change you! In some cases quite literally.

For instance, you might know that flamingos get their pink hue by eating food rich in substances called carotenoids.

HG: Mmm.

MA: There are at least ways that humans can change the color of their skin by eating things.

HG: Oh gosh!

MA: Which of the following is not a real thing that can happen?

Eating too many carrots and turn you orange?

HG: Carotenoids... is the reason that they're called carotenoids. Sorry, I just gave that one away.

MA: Eating too many snails can turn you yellow.

Eating too much lobster can turn you pink.

Consuming too much silver can turn you silvery.

(Buzzer twice)

MA: Yep.

DL: I'm going with the lobster.

MA: You are correct!

SMA: Carrots -like flamingo food- are full of carotenoids. The compounds are actually named after carrots. Too many carrots mean excess carotenoids in your bloodstreams; which can give your skin an orangey tint: a condition known as carotenosis. 

Eating too many incorrectly prepared snails can lead to a parasitic infection called liver flukes: which -as the name implies- affects the liver. Eventually it can cause enough damage to lead to jaundice; which makes you look yellow.

Drinking silver has been tried by some people because they think the metal has some medicinal properties; which of course has never been proven. But people drink it anyway; which is how we know too much of it can cause argyria: a name for when your skin turns an alarming shade of bluish-silver. 

HG: I knew it was one of those.

DL: I used to eat a lot of lobster. Never turned me pink.

HG: You eat a- Dave eats a lot of lobster.

DL: Used to eat a lobster.

HG: You used to eat a lobster?

DL: I used to live.. near Maine.

MG: You know a lobster a day keeps the pink away!

HG: That's what they say.

DL: I don't eat much lobster in Montana.

HG: No, Montana lobster.

DL: Not known for its lobster.

HG Montana river lobster!

DL: Crawfish!

(Explosion)

MA: Okay -while we're on the subject of skin- one feature has turned out to be quite useful: fingerprints.

These days they're mostly famous for helping us solve crimes-

HG: For the fuzz.

MA: -for the fuzz- but they seem to have originally evolved to help humans grasp things. 

We're not the only species with fingerprints, though: primates have them; as does one other species of animal.

Is it: koalas? Raccoons? Beavers? Or Skunks?

HG: That's really weird: that only one other in that -they would- all of those animals...

DL: Koalas? Skunks? Beavers?

MA: Koala, raccoon, beaver, skunk.

HG: That sounds like -if you combined all those animals- they'd be pretty awesome.

DL: (Laughs)

MA: A... Kroc-a-skunk.

HG: Krocaskunk?

MA: Yes?

HG: I was just wasting time until Dave guessed.

DL: I'm gonna go raccoon!

MA: Incorrect!

(Buzzer)

HG: Koala!

MA: Correct!

HG: Ah! I figured they were the weirdest one of all of them. There aren't a lot of things like koalas.

DL: It is true: living in Australia.

SMA: Humans and other primates have fingerprints because we shared an ancestor who also had fingerprints. But in koalas they're a case of convergent evolution: they developed a similar trait because of similar needs.

It's thought their fingerprints help koalas pick off and hang onto all those leaves that they eat.

MA: Sometimes a species will evolve to the point where it doesn't need a particular trait anymore; which is how humans ended up with some vestigial characteristics like wisdom teeth.

Then there's the vomeronasal organ -or VNO- which in other animals functions kind of like a second nose. It's part of a whole separate olfactory system.

For a long time scientists have debated whether humans have a VNO, and many studies have found evidence of a tiny bit of tissue at the base of the nose, that probably used to be our second nose.

But what was its original purpose?

Was it: to detect pheromones in other humans? 

To sense infections in other humans?

HG: Hmm.

MA: To detect prey?

Or to sense chemicals produced by rotting food?

(Buzzer)

HG: Pheromone... thingy.

MA: Correct!

SMA: The human VNO isn't connected to the brain at all anymore; it just kinda sits there -a little extra weight, clinging to your nose.

But at some point -in our distant past- it helped us distinguish other members of ours species -and pick a mate.

Humans, it seems, can still detect pheromones, but we don't have an entire second sense of smell for it, the way some other animals do. 

HG: Ah! I just figured that was the thing that we're not super good at.

DL: I was going to go with rotting food.

HG: We're good at smelling rotten food, though. Ah, too good.

DL: But not good at pheromones.

HG: I don't think so.

MA: How are those pheromones?

HG: You just smell good! You smell good.

MA: Good. Put some extra pheromones on, I guess.

Okay! We've reached our double or nothing round.

(Explosion)

(Anticipation noises from HG and DL)

MA: So this is where you're going to wager... some number of points. How many points do we have?

Woman off camera: Uh, Hank has 1200, Dave has 800.

DL: Ugh.

HG: Ooof!

MA: Hank has 1200 points. Dave has 800 points. So you can wager any or all of your points.

DL: There's a scorekeeper now? There wasn't a scorekeeper last time.

MA and HG: (Laughs) We just made one up.

DL: Aranda was just winging it last time.

MA: (Clears throat) I can tell you that the subject of the next question is the environment.

HG: Okay.

MA: So you guys are going to make your wagers now, we're going to a commercial break.

Welcome back! You guys ready?

HG: We're ready!

MA: Wagered some points?

So for a lot of people, drinking water comes from nearby reservoirs. But the problem of drinking from open bodies of water is that sometimes things can go wrong. That's why water protection agencies regularly monitor reservoirs for things that are potentially harmful -or contaminating.

The Ivanhoe Reservoir in California provided fresh water for more than half a million residents of Los Angeles. Then in 2008, the Department of Water Protection found something unusual.

To solve it, they poured millions of softball-sized black plastic balls into the water. Then they kept using the reservoir for the next 6 years or so.

But why did they put all those balls there?

Was it to:use additives in the plastic to kill bacteria?

Use additives in the plastic to neutralize a harmful chemical?

Block sunlight, preventing algae from growing?

Or block sunlight, preventing a reaction that would've produced a harmful chemical?

HG: Oh this is- We just write it down.

DL: Oh... well... I'm really not

HG: Yeah, well I don't-

DL: -used to the show.

HG: I don't know either.

DL: Okay...

A, B, C or D?

HG: Yeah, D... A, B, C or D.

HG: Alright!

MA: You guys ready?

HG: We're ready!

MA: Show your answers!

MA: Hank, you got the correct answer.

(Bell)

MA: Dave, unfortunately C is incorrect. 

(Slide whistle)

DL: (Groans)

HG: (Groans)

SMA: When they tested in 2007, surveyors realized it contained high levels of bromate. That was a problem because they didn't want hundreds of thousands of people to lose access to drinking water, but they also didn't want them to have a higher likelihood of getting cancer.

Scientists knew that bromate forms when bromide and chlorine are exposed to sunlight. They couldn't do anything about the bromide, because it came from the ground water. And they needed the chlorine to kill bacteria in the water.

So, they figured they'd have to do something about the sunlight, while they constructed two new reservoirs. The simplest solution turned out to be purchasing hundreds of thousands of little plastic balls, which floated on top of the water like a huge, bumpy tarp.

The new reservoirs are being built underground this time. The first was completed in 2014, and the second will be done sometime in 2017.

But for 6 years, those shade balls did their job.

MA: So that's our show! Hank is our winner: you won for Paul!

HG: Ha! Paul! You will get slightly more things than Daven!

MA: Sorry, Daven!

HG: Slightly.

DL: Sorry, Daven!

MA: Thank you for watching this episode of SciShow Quiz Show! If you want to support us on Patreon, you can go to patreon.com/scishow. And don't forget to go to youtube.com/scishow, and subscribe.

(Outro)